There were calls to end the live export trade earlier this month after footage was broadcast of an Emanuel Exports-chartered voyage to the Middle East on which 2400 sheep died in filth and extreme heat.

The vessel, the Awassi Express, was held up in Fremantle Port for about three weeks because the Australian Maritime Safety Authority ordered the operator to improve its ventilation system.

AMSA gave the Awassi the all-clear on Tuesday but Emanuel is instead using the Al Messilah, which began loading about 70,000 sheep and 12,000 cattle on Sunday morning.

Stop Live Exports held a snap rally at the port, attended by about 200 people, within hours.

The group's WA convenor Katrina Love vowed to return to monitor the loading, which continues on Monday.

She said the Al Messilah was older than the Awassi and had its own history of animal suffering.

More than 3000 sheep died from extreme heat on board the Al Messilah in 2016, when it had also been chartered by Emanuel Exports.

"What is the purpose of having regulations in place when exporters like this are just ignoring them?" Ms Love told AAP.

Meanwhile, another controversial livestock ship, the Bader III, is expected to arrive in Fremantle late on Friday, bound for the Middle East.

Ms Love said protesters would "welcome" the Livestock Shipping Services-chartered vessel, which drew protesters in Adelaide before it left port.